Features: Both suitable for professionals and beginners. The two sides of the pen have firm and heavy metal balls and unique buffer spring which greatly increase the weight, balance and stability. Both the two sides have elastic soft gum which can prevent the instep from falling and being broken. Specifications: Material: Non-slip coating plastic, metal Color: Black, White Size: 22 cm Package includes: 2 x Rotating pens 2 x Storage tube Note: The product does not include the refill, can not write as ordinary writing pen.